The invention, generally, relates to systems for interconnecting computers electronically for the purpose of information exchange and, more particularly, to a new and improved system to permit communication between a Manufacturing Automation Protocol (MAP) network utilizing the Common Application Service Elements (CASE) hereinafter referred to as a MAP CASE network, and a non-MAP connection-oriented network.
Earlier this decade, a major manufacturer of automobiles in the United States found that a significant percentage of the cost of automating its factories was related to developing ways to provide interconnections between equipment made by different vendors. Actually, there are a large number of vendors who make and sell data processing computers specifically for the factory environment, and while these vendors usually also make and sell interconnecting devices for their equipment, such interconnecting devices will typically operate only with the equipment sold by each vendor.
To a large device, this situation has been responsible for the emergence of "islands of automation", which are localized areas of automation on the factory floor that are isolated from other areas of the factory in terms of electronic exchange of information. This lack of electronic exchange of information between various vendor's equipment is a major roadblock to achieving total factory automation.
The Local Area Network, or LAN, technology that is commonly used in offices is not suitable for a factory environment where machines generate spurious electronic signals that interfere with computer operations. Therefore, a network standard was developed, called Manufacturing Automation Procol, or MAP, that is suitable for use with computer equipment of many types and origins in the factory environment.
It is expected that as the Manufacturing Automation Protocol technology matures, it will receive wide acceptance throughout the industry for application in newly designed and installed manufacturing systems. However, because the MAP network specification is still relatively new and still evolving, data processing computer interfaces to the MAP network are still relatively expensive when compared to similar data processing computer network interfaces for many previously defined networks. Further, there are a number of pre-MAP connection-oriented networks already installed and operational. Owners of such networks are reluctant to remove these networks in order to install new MAP networks.
A network which combines the multi-vendor interconnection and factory floor suitability features of the MAP network with the already installed non-MAP connection-oriented network to produce a Virtual MAP network would be highly desirable. Such a Virtual MAP network preserves the integrity and characteristics of the MAP CASE connection from the computer attached to the MAP network to the computer attached to the non-MAP connection oriented network. This is done in such a manner so as to guarantee the end-to-end delivery of data, preserve the MAP CASE connection state information and present it to both ends of the Virtual connection, and reflect the MAP CASE network naming conventions across the Virtual MAP CASE Connection.
The benefits of such a Virtual MAP network include the ability to selectively install the MAP network where needed to interconnect manufacturing equipment from multiple vendors for the purpose of electronic data exchange, while at the same time, utilizing the already installed non-MAP connection-oriented network and associated data processing computers and interfaces to the non-MAP network. In the future, if technical and business reasons dictate, the non-MAP network could be incrementally replaced with the MAP network with a minimum impact on various user programs developed to operate in the Virtual MAP network.
Therefore, to provide this Virtual MAP network, an interface system is needed that will permit any MAP CASE user program running in any data processing computer attached to the MAP CASE network, to establish a MAP CASE connection and exchange data with another MAP CASE user program running in any other data processing computer attached to a non-MAP connection-oriented network.